gcc/ada/switch.adb

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT COMPILER COMPONENTS                         --
   4 --                                                                          --
   5 --                               S W I T C H                                --
   6 --                                                                          --
   7 --                                 B o d y                                  --
   8 --                                                                          --
   9 --                                                                          --
  10 --          Copyright (C) 1992-2001, Free Software Foundation, Inc.         --
  11 --                                                                          --
  12 -- GNAT is free software;  you can  redistribute it  and/or modify it under --
  13 -- terms of the  GNU General Public License as published  by the Free Soft- --
  14 -- ware  Foundation;  either version 2,  or (at your option) any later ver- --
  15 -- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
  16 -- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
  17 -- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
  18 -- for  more details.  You should have  received  a copy of the GNU General --
  19 -- Public License  distributed with GNAT;  see file COPYING.  If not, write --
  20 -- to  the Free Software Foundation,  59 Temple Place - Suite 330,  Boston, --
  21 -- MA 02111-1307, USA.                                                      --
  22 --                                                                          --
  23 -- GNAT was originally developed  by the GNAT team at  New York University. --
  24 -- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). --
  25 --                                                                          --
  26 ------------------------------------------------------------------------------
  27
  28 package body Switch is
  29
  30    -------------------------
  31    -- Is_Front_End_Switch --
  32    -------------------------
  33
  34    function Is_Front_End_Switch (Switch_Chars : String) return Boolean is
  35       Ptr : constant Positive := Switch_Chars'First;
  36
  37    begin
  38       return Is_Switch (Switch_Chars)
  39         and then
  40         (Switch_Chars (Ptr + 1) = 'I'
  41          or else (Switch_Chars'Length >= 5
  42                   and then Switch_Chars (Ptr + 1 .. Ptr + 4) = "gnat")
  43          or else (Switch_Chars'Length >= 5
  44                   and then Switch_Chars (Ptr + 1 .. Ptr + 4) = "fRTS"));
  45    end Is_Front_End_Switch;
  46
  47    ---------------
  48    -- Is_Switch --
  49    ---------------
  50
  51    function Is_Switch (Switch_Chars : String) return Boolean is
  52    begin
  53       return Switch_Chars'Length > 1
  54         and then Switch_Chars (Switch_Chars'First) = '-';
  55    end Is_Switch;
  56
  57    ------------------------
  58    --------------
  59    -- Scan_Nat --
  60    --------------
  61
  62    procedure Scan_Nat
  63      (Switch_Chars : String;
  64       Max          : Integer;
  65       Ptr          : in out Integer;
  66       Result       : out Nat)
  67    is
  68    begin
  69       Result := 0;
  70
  71       if Ptr > Max or else Switch_Chars (Ptr) not in '0' .. '9' then
  72          raise Missing_Switch_Value;
  73       end if;
  74
  75       while Ptr <= Max and then Switch_Chars (Ptr) in '0' .. '9' loop
  76          Result := Result * 10 +
  77            Character'Pos (Switch_Chars (Ptr)) - Character'Pos ('0');
  78          Ptr := Ptr + 1;
  79
  80          if Result > Switch_Max_Value then
  81             raise Bad_Switch_Value;
  82          end if;
  83       end loop;
  84    end Scan_Nat;
  85
  86    --------------
  87    -- Scan_Pos --
  88    --------------
  89
  90    procedure Scan_Pos
  91      (Switch_Chars : String;
  92       Max          : Integer;
  93       Ptr          : in out Integer;
  94       Result       : out Pos) is
  95
  96    begin
  97       Scan_Nat (Switch_Chars, Max, Ptr, Result);
  98
  99       if Result = 0 then
 100          raise Bad_Switch_Value;
 101       end if;
 102    end Scan_Pos;
 103
 104 end Switch;